Surveyor's Chain Article taken from "Backsights" Magazine published by Surveyors Historical Society THE SURVEYOR'S CHAIN To surveyors and collectors alike, the link chain symbolizes a rugged era, when surveying tools and techniques were literally defining America. The chain was a precision part of a surveyor's equipment and, as such, had to be calibrated and adjusted frequently, yet was sturdy enough to be dragged through rough terrain for years. Owning a link chain now captures a bit of this glorious past; to heft it enhances the kinship one feels with the surveyor who toiled in the field long ago. As collectors, we need to identify the type of chain we own, in order to understand its history. Each chain bears the clues of its use, such as the wire gauge used, the materials and design used, the lengths of the whole and of each link, the manufacturer's stamps, the presence or absence of brazing, the tally-tags, and the presence or absence of linking rings. Noting these components will make it possible to approximate the date and purpose of your link chain with the aid of period manufacturer's catalogs.

The following is a nicely detailed account from the 1910 Manual of the Principal Instruments used in American Engineering and Surveying, published by the W. & L. E. Gurley Company of Troy, New York. Sizes of Wire - The sizes and diameters of iron and steel wire commonly used in making surveyor's and engineer's chains are as follows: No. 8, .162 inch; No. 10, .135 inch; No. 12, .105 inch; No. 15, .072 inch; and No. 18, .047 inch. Land Surveyor's Chain - The ordinary Gunter's or surveyor's chain is sixty-six feet or four poles long, and is composed of one hundred links, connected each to each by two rings, and furnished with a tally mark at the end of every ten links. A link in measurement includes a ring at each end, and is seven and ninety two one hundredths inches long. In all the chains which we make the rings are oval and are sawed and well closed, the ends of the wore forming the hook being also filed and bent close to the link, to avoid kinking.

The oval rings are about one third stronger than round ones. Handles - The handles are of brass and form part of the end links, to which they are connected by a short link and jam nuts, by which the length of the chain is adjusted. Tallies - The tallies are of brass, and have one, two, three or four notches, as they mark ten, twenty, thirty or forty links from either end. The fiftieth link is marked by a rounded tally to distinguish it from the others. Half Chains - In place of the four pole chain just described, many surveyors prefer a chain two rods or thirty three feet long, having only fifty links, which are counted by tallies from one end in a single direction. Iron and Steel Wire - Our surveyors' chains are made of Nos. 8 and 10 refined iron wire, and of Nos. 8, 10, 12 and 15 best steel wire. Steel chains are preferred on account of their greater strength, although they are more expensive than those of iron.

Engineers' Chains - Engineers' chains differ from surveyors' chains, in that a link including a ring at each end is one foot long, and the wire is of steel Nos. 8, 10 and 12. They are either fifty or one hundred feet long, and are furnished with swivel handles and tallies like those just described. Brazed Steel Chains - A very light and strong chain is made of No. 12 steel wire, the links and rings of which are securely brazed. The wire is of a low spring temper, and the chain, though light, is almost incapable of being broken or stretched in careful use. Our brazed steel chains have been found exceedingly desirable for all kinds of measurement, and for the use of engineers upon railroads and canals have very generally superseded the heavier chains. Vara Chains - The meter is used as a standard measure of length in many countries, and chains of ten and twenty meters are often ordered. The chains are made of iron or steel wire, each meter being divided into five links. As a meter is 39.371 inches long, a link, including a ring at each end, measures 7.874 inches.

A ten meter chain has fifty links and a twenty meter chain one hundred links. Each meter is marked with a round brass tally numbered from one to nine in the ten meter chain, and from one to nineteen in the twenty meter chain. Marking Pins - In chaining, eleven marking pins are needed, made either of iron, steel or brass wire, as preferred. They are about fourteen inches long, pointed at one end to enter the ground, and formed into a ring at the other end for convenience in handling. Marking pins are sometimes loaded with a little mass of lead around the lower end, to serve as a plumb when the pin is dropped to the ground from the suspended end of the chain. How to Make a Gunter's Chain How to Make a Gunter's Chain by David Manthey Copyright 2002 by David Manthey. Click on images for a larger version. Introduction This is how I made a Gunter's chain (also known as a survey chain). The total length of a Gunter's chain is 4 poles (66 feet), and the chain is composed of 100 links. Each link is joined to the next by one or two round rings; I chose to use two rings.

The link plus associated rings are exactly 7.92 inches in length. The first and last links are handles. Every ten links there is a brass tag that identifies the number of links. At link 10 and link 90, the tag has one point. At link 20 and link 80, the tag has two points. At 30 and 70, three points, and at 40 and 60, four points. At link 50, the halfway point, a round tag is used. I chose to use rings with an inner diameter of 1/2 inch. I also used this as the nominal inside diameter of the eyes of each link. This is a typical value for historic chains. Materials Wire - 14-gauge galvanized steel wire. I purchased a 1/4 mile spool of this from Agway (the local farm supply store) for $20. It was intended for use with electric fences. This is probably enough to make 8 chains. Historically, chain wire ranged in size from 14 gauge to 8 gauge. Brass Tags - Used for the ten-link markers.

I ordered a bag of 25 from McMaster-Carr, part 1540T22, 1 1/4" diameter, with ear. This cost around $8 plus shipping. Nine are needed (plus any that get fouled up). Link Jig - This is a wooden board with three holes drilled in it. There are two 1/2 inch diameter holes (the inner diameter of the eyes of the links), at a center-to-center distance of 6.42 inches (7.92 minus the inner diameter of the rings multiplied by the number of rings and minus the inner diameter of the link eye). There is a small hole near one of the 1/2 inch holes that is a little larger than the diameter of the wire. The placement and size of this hole need not be exact. Dowels for Link Jig - These are two dowels of equal length and the same size as the inner diameter of the eye of the link. In this case, I made them 4 inches long and 1/2 inch in diameter. Ring Winder - This is a dowel the same diameter as the inner diameter of the rings with a hole drilled through near one end.

The hole needs to be slightly larger than the diameter of the wire. Tools Wire Snips - These are the most frequently used tool. They need to be able to cut the wire easily, not be too tiring, and have small enough jaws to fit inside a coil of wire with the chosen ring diameter. Pliers - These are used to help shape the links, close rings and link eyes that have gaps, and to generally manipulate the rings. The round section designed for gripping nuts is useful to grab rings and eyes. Needlenose Pliers - These are used to help form the neck on the links immediately adjacent to the eye. They are also useful for flattening the brass tags after they have been cut. Screwdriver - A flathead screwdriver is useful for prying apart link eyes and rings. Metal File - This is used to deburr the edges of the brass tags. A triangular file is useful because it can reach into the 'V' on the tags. Wood Saws - Used for making the jig and cutting the dowels to length. Drill and Bits - Used for making the jig and boring a hole in the ring-winder.

A bit the size of the inner diameter of the link eyes is needed, plus a bit slightly larger than the diameter of the wire. I used 1/2 inch and 3/32 inch bits. Tape Measure - (not shown) - One needs to verify the chain somehow. Although the average carpenter's tape measure isn't as reliable as actual survey equipment, it is adequate for a rough chain such as this. Pencil - (not shown) - For marking the jig, the tags, and other items. Safety Equipment - (not shown) - Eye protection is a must. Gloves are a good idea. Making Rings For a chain with two rings per link, 198 rings are needed. Additionally, each of the nine tally tags is held on by another ring, bringing the total to 207 rings. It is convenient to make a few rings as one is making the links (see the section on making links below). However, some rings will need to be made by themselves. Step 1 - Cut some wire - Cut off a comfortable working length of wire. I found that less than four feet was too little to bother with, while more than eight feet was too much of a pain to work with.

If you use an automated winder (see comments on later steps), you will want to work with more wire at a time. I found that the appropriate length was roughly 1 1/2 loose coils off of the spool of wire. Step 2 - Put the wire on the winder - Insert one end of the wire into the hole near the end of the winding stick. The wire should go most of the way through the hole but not emerge from the other side (otherwise, there will be a sharp point of wire waiting to scratch you). Bend the wire over and begin to wrap it around the winder. At first it is easy to turn the winding stick, but after a while it becomes easier to grip the winding stick firmly and spin the wire about it. Step 3 - Wind all of the wire - Continue winding until all of the wire is on the winding stick. Be sure to lay the wire on evenly with no overlap. Also be sure that the wire is snugly against the stick. An automated winder can be made by mounting the winding stick between two upright boards (though a hole drilled in each) and spinning the winding stick with a drill. Wear gloves.

Websites that detail how to make chainmail have drawings for such a device. Step 4 - Remove the wire from the winder - Use the wire snips to cut the wire just where it comes out of the starting hole. The wire in the starting hole can now be removed and discarded. The coil of wire will slide off the of the winding stick. Step 5 - Cut the rings - Use the wire snips to cut the rings apart. Cut along the length of the coil. There will be a small amount of waste at each end of the coil. Cut straight through. Often I can cut several rings at once; it is limited by how far the wire snips will fit into the coil. Go slowly on the last few rings to avoid shooting bits of wire across the room. Done - Set the rings aside for use in assembling the links and attaching the tags. Making Links A chain needs 98 regular links and two handle links. The length of the link plus the inbetween ring(s) must be 7.92 inches. When winding the links, one need not be perfect; the length of the links can be adjusted as the chain is assembled. A winding jig is needed to make links. See the materials list for details.

Step 1 - Cut some wire - Cut off enough wire to make a sensible number of links. I found that I could make seven links at a time. If I attempted to make more, my needlenose pliers didn't have enough jaw depth, and the additional links tended to be short. Around 12 inches of wire is needed per link. I found that the appropriate length was roughly 2 loose coils off of the spool of wire. Step 2 - Start the wire - Put one end of the wire in the small hole in the jig. Bend the wire over 90 degrees so that the coil is flat with respect to the jig board. Step 3 - Wind around the first dowel - Insert the jig dowels into the holes. Bend the wire around the dowel nearest to the starter hole, keeping it tight to the dowel. Start winding on the side furthest from the second dowel (henceforth referred to as the outside of the dowel), and go around 1 1/2 times. Do not overlap the wire; rather, put the second coil above the first. There will be one level of wire at the inside of the dowel and two on the outside.

Step 4 - Wind around the second dowel - Switching to the opposite side of the second dowel, wind the wire 2 1/2 times around the second post. The wire will form either an 'S' or backwards 'S' shape between the dowels. There will be two levels of wire at the inside of the second dowel, and three levels on the outside. Again, make sure the winding is tight to the dowel and that the wire does not overlap. Step 5 - Wind the rest of the links - Continue in the same manner, switching sides when switching dowels. Wind 2 1/2 turns around each dowel. Proceed until the desired number of links are wound. Unless the dowel holes are drilled very precisely in the jig, the dowels will have a tendency to tilt in toward the center, making the later links slightly shorter than the first few links. Although it would be best to prevent this tilting in, winding the later links slightly looser seem to work well enough. Note that the crossing point of the links will not be centered between the two dowels due to the residual curvature of the original wire; this will be corrected for later.

Step 6 - Wind any remaining wire into rings - If there is any significant amount of wire left, wind it around the dowel it is closest to. This can be turned into additional rings to put between the links. Note that two short links will be needed as part of the handles. For these, leave the excess wire (at least a links worth) straight so that it will have only one eye. See the section on handles for details. Step 7 - Form the neck of the links - Use the needlenose pliers to squeeze all of the links a short distance from each of the two dowels. This puts an angled neck into the link, straightens the wire somewhat, and reduces the residual curl from the wire coil. This step is not strictly necessary, but it does make forming the links easier. Step 8 - Remove from the jig - Take the links off of the jig. This is where having removable dowels comes in handy. After removing the links from the jig, use a flat bladed screwdriver to slightly pry apart the inside end of each link junction (the part of the eye where there are two thicknesses of wire). This will make cutting the links easier.

Step 9 - Cut off a link - Use the wire snips to cut off a link. Cut as close to the shaft of the link as is convenient so that the eye is nearly a complete loop. There will be a slight gap. Between each link there is around 3/4 of a ring of scrap. Step 10 - Cut the rest of the links and rings - Use the wire snips to cut off the rest of the links. Also cut any spare rings that were wound. Step 11 - Straighten the links and close the eyes - Lay a link on a flat surface (such as the jig). Flatten any bend in the link. Next take the regular pliers and close each eye. The eye can be closed in two manners: (a) by squeezing it with the jaws of the pliers, and (b) by grabbing the back of the eye (away from the opening) and rolling the eye closed. Method (a) lengthens the link somewhat, method (b) shortens it. Ideally, the final link needs to be 6.92 inches (7.92 less the inside diameter of the rings). Make the gap at the eye as small as possible.

Step 12 - Form the neck near each eye - Form the neck of the link by placing the link on a flat surface, and pushing down on the eyes, keeping the eye opening upwards. The shaft of the link should be fairly straight. Done - The links are ready to be added to the chain. They will most likely need some slight length adjustment at that time. Making Tags A chain needs a tag to mark every ten links, using a total of 9 tags (the ends are not marked by tags). Two tags of each of four shapes are needed, plus one round tag for the center. Historically, the tags varied quite a bit. Step 1 - Mark the tags - Mark the tags for cutting. Many different shapes can be used. I chose to make simple tags based on the premade round ones that I had purchased. Transfer the design to the tags using a pencil. Step 2 - Cut the tags - I used the wire snips to cut the tags. This had the disadvantage that it bent the tags as it cut them. I think a metal bandsaw would be a preferred method. Step 3 - Flatten the tags - Use the needlenose pliers to flatten out the tags. They won't be perfect.

Step 4 - File the edges - Use the triangular metal file to smooth the cut edges and the points on the tags. By angling the file, a very tight corner can be reached. Done - The tags are ready to be added to the chain. Making Handles The handles on the chain form the end links. Specifically, the outside edge of the chain is the point from which things are measured. Historically, chains either had wire handles or cast brass handles. Often, but not always, the handles act as swivels to aid in untwisting the chain. Some chains, but by no means the majority, also had a swivel link somewhere near the center in place of one of the regular links. Step 1 - Cut some wire - Cut off around 14 inches of wire. This will be slightly more than is necessary for a handle. Step 2 - Form the gripping surface - Put three fingers at the center of the wire and bend the wire around the fingers to form an isosceles triangle. Step 3 - Start the neck - At a slight distance more than the width of the grip, bend both sides of the handle inward, leaving an overlap of around 1/2 inch.

Step 4 - Begin wrapping the wire - Starting with whichever side of the neck is further from the grip, fold the wire around the opposite side, pinching it tightly. The wire must be put through the handle. The needlenose pliers work best here. Step 5 - Form the eye - Using the needlenose pliers, form a loop of wire. The loop must be at least as large as the diameter of the wire and no larger than 1/4 inch in diameter. I found it useful to use the regular pliers to grip the wire. Make sure the loop is on the same side of the neck as the grip. Step 6 - Reinforce the eye - Wrap the second side around the first loop. This should either be immediately outside of the first loop or between the first loop and the neck (and always inside of the sides of the handle). Step 7 - Reinforce the base - Continue wrapping the same wire, this time forming another loop on the other side of the neck (away from the grip). Step 8 - Fold in and clip the ends - Fold in the ends of the wires. Use the wire snips to cut them as close as possible to the bulk of the handle.

Fold in any protruding wire. Step 9 - Form one end of a link - Form one end of a link on the link jig. Close the eye and form the neck. The free end should be long enough to form a regular link, plus a few inches (it is easier to work with a long end). Step 10 - Put the link in the handle - Insert the link into the handle so that the eye is on the inside of the handle. The link should spin freely and not have any significant preference in orientation. If, when the free end of the link is rotated and pulled, the eye of the link moves closer and further from the handle grip, then either the handle or link needs some adjustment. The neck of the link can be flattened, and the loop on the handle can be levelled. There will always be a slight preference, but it should be less than a wire thickness in size. Step 11 - Start winding the free end - Insert the free end of the link into the ring winder. Start winding the free end, making sure that the eye formed by the loops of wire on the ring winder are in the correct orientation to form an 'S' shape with the already formed link eye.

Step 12 - Wind to the correct length - Wind the link wire onto the ring winder until the total length of the handle and link (including the eye formed on the winder) is only slightly longer than the correct length. For a chain with two rings between each link, the correct length is 7.42 inches (7.92 minus the inner diameter of half of the rings between the links). This is the distance from the outside of the handle grip to the inside of the far link eye. Step 13 - Cut off and form the second eye - Cut the link and eye off of the ring winder. If there was a lot of extra wire, it is likely that a few rings can also be made. Clip the wire so that an eye can be formed in the same manner as when the links are cut from the link jig. Form the eye and neck. Ideally, the combined link and handle will be the correct length or a little longer (it is easier to shorten a link than lengthen it). Done - The handle is ready to be added to the chain. Assembling the Chain The chain can be assembled as the various links, rings, handles, and tags are finished.

This is more satisfying than waiting until all of the parts are made, as the progress is more evident. If the chain is to be hardened, the tags should not be added until after hardening. Step 1 - Attach a ring to a link - The links are attached to each other with the rings. The handle is treated as an ordinary link for assembly purposes (except, of course, that the handles go at either end of the chain). Place a ring through the eye of a link. Close the ring using the pliers, making sure that the gap is small and the wire ends are lined up. Step 2 - Attach another ring and another link - Put another ring through the ring that was just added. Before closing the ring, put the ring through another link. Close the ring as before. Step 3 - Shorten the link if necessary - Compare the link and the associated rings to a ruler to make sure it is the correct length. It is best to adjust a series of links in a row to reduce the likelihood of error build-up. I found it easiest to mark a vertical section of wall for a distance of ten links, then hang the chain from a hook at the top. This provided a small tension on the chain.

I adjusted the links starting at the top and working my way down. If a link is too long, it can be shortened by grabbing the back of the eye with the pliers and rolling the eye toward the center of the link. Step 4 - Lengthen the link if necessary - The link can be lengthened by crushing the eye somewhat. It can also be lengthened by unrolling the eye (the opposite of the preceding step), then squeezing the open gap in the eye closed. Step 5 - The neck can also be adjusted - The neck can be flattened to elongate the link or bent more to shorten the link. This is generally a smaller adjustment than working on the eye. Continue attaching the links until the entire chain is assembled. If the chain is to be hardened, it should be done at this time. Step 6 - Attach the tags - Attach a tag every ten links. The tag is attached with another ring. It doesn't matter to which of the two inter-link rings the tag ring is attached.

The tag with 1 point goes at link 10 and 90, 2 points at 20 and 80, 3 points at 30 and 70, 4 points at 40 and 60, and the round tag at 50. Remember that the handle is a link. Done - The chain is complete. The chain should be verified against a standard to make sure that it is exactly 66 feet in length. Note that the tension with which the chain is held will change its length. Therefore, make sure that when verifying the chain length the tension is the same as that which will be used in the field. Hardening (optional) Because the chain is made from mild steel, it will have a tendency to bend under use. This can be reduced by hardening the steel. To harden steel, the steel needs to be heated to 1600 degrees Fahrenheit, then quenched in water. This makes the steel hard, but brittle. To reduce the brittleness, the steel is then tempered by raising it to 400 degrees Fahrenheit for an hour or so, and then letting it cool normally.

If the steel does not have enough carbon in it, it will not harden. Also, if the steel is galvanized, the zinc will melt or vaporize in the hardening process. Historically, many chains were hardened. I have not hardened my chain. Brazing (optional) Historically, some chains had the gaps in the link eyes and rings brazed closed. The chains I have examined look like they were soldered with a lead or silver solder. Initially, I didn't braze my chain. However, once I took the chain into the field, I found that it would occasionally come apart, especially when dragging it through brush. While one could be careful and still use the chain, I wanted to be able to use it properly, so I decided to braze it. Brazing Materials Muriatic Acid - Because I started with galvanized wire, I needed to remove the zinc before I could braze the chain. Muriatic acid does this quite efficiently, though it is quite toxic. Be sure to follow all the proper safety guidelines when handling the acid. Mapp Gas Torch - I used a mapp gas torch to heat the chain to braze it. This is similar to propane, but burns hotter.

Propane would probably have been sufficient. Solder - I used a lead/tin solder, primarily because it was available. The solder should be roughly the thickness of the wire used for the chain. Very thick solder doesn't work well, and thin solder is more annoying to apply. Water - (not shown) - For quenching the brazed links and for rinsing the muriatic acid off of the links. Brazing Tools Pliers - In addition to the common-sense safety items, I used a pair of pliers for manipulating the hot links. This wasn't often necessary, as the neighboring links didn't heat up and could be used to move the working area. Glass Jar - I used a glass jar for the muriatic acid. This kept the open surface area to a minimum, but still allowed easy immersion of the areas to be brazed. Bucket - For holding the rinse/quench water. Grill - (not shown) - As a work surface, I used a barbeque grill. There may be a better choice, as I ended up splashing some of the solder on the grill, but at least the grill was not flammable in any manner, and allowed the placement of very hot items on it.

Brazing Process Note: I brazed the chain outside, away from my camera equipment. Therefore, the following pictures are a recreation of the brazing process. The pictures are representative of what needs to be done, but do not have the same exactness as the rest of the description. Step 1 - Remove the Zinc - Put the junction between two links into the jar of muriatic acid. Hydrogen gas bubbles off from the links and rings as the acid reacts with the zinc. After many links have been done, the acid will become tinged with suspended zinc chloride. I made sure that at least half the length of the link was submerged in the acid, so that the entire chain would be free from zinc when I was complete. The brass tags are not substantially affected by the muriatic acid, so I did not remove them prior to brazing. This allowed the rings holding on the tags to also be brazed. Also, I dipped the handles into the muriatic acid; this was solely to obtain a uniform appearance to the final chain. Step 2 - Braze - Use the torch to heat the link eyes and rings. When the wire is hot enough, touch it with the solder.

When this is done optimally, the solder melts and flows to fill the slight gap between the link eye and the link shaft or the gap between the ends of the rings. Sometimes I had to reheat the wire and reapply the solder. Step 3 - Rinse and quench - Put the brazed links into the bucket of water. This stops the acid from further etching the steel wire, and also hardens the solder. Step 4 - Inspect the brazed points - Check each braze point carefully to ensure that it is fully joined and reasonably strong. If there is a problem, braze the area again. Repeat all of the steps for all of the link eyes and all of the rings. Done - The chain can now be used vigorously. It is strong enough that I and an assistant can carry it over obstacles by keeping enough tension on the two ends. I rinsed the entire chain once more, then oiled it lightly with WD-40 to keep it from rusting. Completed Chain Here are some photographs of the completed chain. The first three photographs are of the chain prior to brazing. The rest of the photographs are of the chain after it has been brazed and has been used in the field several times.

I tied strips of white cloth to the handles and every 25 links to make the chain easier to see; otherwise it practically vanishes when placed on the ground. chain See also: Ramden’s chain and the Rathborn chain . Various units of length used for surveying in the English-speaking world, all consisting of 100 links. The surveyor’s chain of 100 links is identified with Edmund Gunter, who introduced such a chain in 1620, although chains divided decimally had existed earlier. The convenience of this decimal division was the cause of the chain's success; among other advantages, an area 1 chain by 10 chains was an acre. The abbreviation is “ch”. 1 When “Gunter's chain” is used without qualification, and always in the United States, the unit is (17th century – present), = 1⁄10 furlong = 4 perches= 22 yards = 66 feet = 20.1168 meters. In the United States these units are based upon the survey foot , not the international foot.

A square chain = 4,356 square feet (approximately 404.686 square meters). One link = 7.92 inches, a hundredth of a chain. The square link is a unit of area, = 62.75 square inches (404.686 square centimeters). sources 1 Knowing the negligence of surveyors in checking their chains, I borrowed one that had been tried about a year before in this office, and which had been used for that period in the service of a civil engineer. Upon trying it with my standard, I found it thirteen inches too long. The person who used it said he knew twenty other chains then in use that must be just as bad. The effect of this error would be this; if I possess a square mile of land, or 640 acres, this surveyor, with the chain in question, would report the content to be 619½ acres, so that selling my land at say 30l. an acre, I should lose 615l.

In the colonies this evil is very serious; for in setting out county and parish lines by chains of different lengths, the discordance and confusion among the details is endless, and will at some time cause dissatisfaction. In 1820, the Solicitor-General to a colony, and the agent of a nobleman who had possessions there, informed me that the discrepancies in the admeasurements were enormous. The chain to which I have alluded was one of the best kind. The error was chiefly caused by the stretching of the wire itself, not one of the links or rings having opened; there was nothing in its appearance to indicate that it was incorrect, except that it was a little worn, and the surveyor would have continued to use it in that state as long as it would have held together. He had never been instructed that during a survey a chain should be frequently checked and adjusted by a standard. Strange as this may appear, I believe it to be a common case. Surveyors in general have no proper standards by which to check their chains and measures; and as regards actual practice, it will be found that most measures can be traced to no better authority than to carpenters' rules, no two of which agree.

The standards offered to the public are usually brass scales at the price of about eight guineas, but, owing to their delicate nature and high price, they are little used. Report of the Commissioners Appointed to Consider the Steps to be Taken for Restoration of the Standards of Weight and Measure. London: Printed by W. Clowes and Sons for Her Majesty's Stationery Office, 1841. Page 73. Information from Samuel B. Howlett, “Chief Draftsman in the Royal Engineer Department; in Report to the Inspector General of Fortifications.” 2 THE CHAIN-- There are two kinds of chain in common use, the Surveyor’s (or Gunter’s) Chain, and the Engineer’s Chain. Gunter’s chain is 66 feet long, and its use is confined chiefly to land surveying on account of its simple relation to the acre and to the mile. 1 Gunter's Chain = 4 Rods = 100 Links 1 Mile = 80 Chains 1 Acre = 10 Square Chains Evidently each link is 66/100 of a foot (or 7.92 inches) long.

The inch, however, is never used in surveying fieldwork. The engineer’s chain is 100 feet long and is divided into one hundred links of one foot each. Each end link is provided with a handle, the outside of which is the zero point, or end, of the chain. In these chains, every tenth link counting from either end is marked by a brass tag having one, two three, or four points corresponding to the number of tens which it marks. The middle of the chain is marked by a round tag. In the engineer's chain then the 10-ft. and 90-ft. points, the 20-ft. and 80-ft points, etc., are marked alike; hence it is necessary to observe on which side of the 50-ft. point a measurement falls in order to read the distance correctly. Distances measured with the surveyor’s chain are recorded as chains and links, (or in chains and decimals); while those measured with the engineer's chain are recorded as feet and decimals. On account of the large number of wearing surfaces and the consequent lengthening with use, the chain should be frequently compared with a standard of length ...

It may be adjusted to agree with the standard, by means of a nut at the handle, which allows the length of the chain to be altered by lengthening or shortening the end link. Charles B. Breed and George L. Hosmer. The Principles and Practice of Surveying. Vol 1. 3rd edition. New York: John Wiley & Sons, 1908. 3 The simplest of these [types of survey] is the "Chain Survey," but this is only suitable for moderately small areas. The chief appliances used are the chain, tape, arrows, ranging rods, offset staff, and occasionally a cross staff, optical square, box-sextant, or prismatic compass. The Chain is generally divided into 100 links, sometimes into 50— but there are several varieties and lengths in ordinary use. The links are composed of lengths of iron or steel wire, and—except at the centre of the chain, and at the 25th link from each end, where swivel joints (S, Fig. 2) are provided—these are connected at their extremities by three small oval rings, preferably welded.

At every 10th link from each end of the chain a brass tag or teller is fastened to the small central connecting ring. The teller which has only one point indicates ten links from either end of the chain—i.e. the 10th or the 90th link measuring in the same direction; that with two points marks the 20th or the 80th link ; three points indicate the 30th or the 70th link; four points the 40th or the 60th link; and a circular tag the centre of the chain. The brass tellers are sometimes designed to be inserted in the length of the chain, but though less liable to catch in hedges, etc., they are perhaps hardly as distinctive as the usual type. The ends of the chain are furnished with brass handles attached by means of swivel joints, and the length of 100 links is measured from the outside of one handle to the outside of the other. The Gunter’s chain—so named after its inventor—is generally used by the Land Surveyor. It is 66 ft.

in length, each link measuring 7.92", and is very convenient when it is required to calculate areas in acres and decimals of an acre, since 10 sq. chains = 1 acre : also when linear dimensions are required in miles and furlongs, since 10 chains = 1 furlong and 80 chains =. 1 mile. When the term “chain” or “link” is used in a general sense, without reference to any particular unit of measurement, the Gunter's chain is inferred. The Engineer's chain is 100 ft. long, each link being 1 ft. in length. It is heavier than the Gunter's chain, but being longer does not need to be laid down so frequently in the measurement of a definite distance; for this reason there is less liability to error from the inaccurate marking of the ends of the chain. Again, as the levelling staff is usually graduated in feet and decimal parts of a foot, this chain is more convenient than the 66 ft. chain when used in connection with levelling or tacheometric operations. In municipal work, too, the 100 ft.

chain is employed, as, in this case, dimensions are required to be expressed in yards, feet, and inches. Metre chains are also in use, the commonest lengths being 10, 20, and 25 metres. They are subdivided into one-fifth parts of a metre and tallied at every two metres from each end. W. Norman Thomas. London: Edward Arnold, 1920. 2 In Scotland, Gunter's chain, still of 100 links, was 4 falls long = 74 feet (= 22.5552 meters). The link was 8.88 inches. Through a misdefining in the mathematical literature of the Scots ell and consequently of the fall, beginning with Colin McLaurin’s comments in an edition of 1745 of David Gregory’s Treatise of Practical Geometry, the Scots chain came to be described in print as 74.4 feet long. It is not known if this length was actually used by surveyors. The matter is discussed in Connor and Simpson . 3 In Ireland, a link of Gunter’s chain, again of 100 links, was 10.08 inches.

This value adapted it to the Irish acre. NMAH | Surveying & Geodesy | Chain, Tape, and Base Bar Chain, Tape, and Base Bar Chains and tapes have been used to measure horizontal distances since the early 17th century, if not before. In England in 1616, Aaron Rathborne mentioned "the making and use of the Decimal Chayne, used only by myself." This chain had ten links and measured 1 pole (16.5 feet) overall. In 1620, Edmund Gunter introduced a chain with 100 links that measured 66 feet (4 poles) overall. For convenience, surveyors sometimes used a Gunterâ€™s chain with only 50 links, that measured 33 feet (2 poles) overall. In 1664, Vincent Wing introduced a chain with 80 links, that measured 66 feet overall; shorter versions with only 40 links were also known; in the late 19th century, a Wing chain was sometimes known as a Pennsylvania chain.

An engineerâ€™s chain has 50 or 100 links, and measures 50 or 100 feet overall; this form came into use in the 19th century. A vara chain has 50 or 100 links, and measures 10 or 20 varas. A metric chain has 50 or 100 links, and measures 10 or 20 meters. James Chesterman of Sheffield, England, patented a cloth tape reinforced with fine wire in 1843. He began making steel tapes in 1853. Tapes of steel alloys with a very low coefficients of expansion were introduced around the turn of the century. Base bars were used for precise geodetic work. Ref: David Krehbiel, "Chain, Surveyorâ€™s" in Robert Bud and Deborah Warner, eds., Instruments of Science (New York and London, 1998), pp. 97â€“98. Collection: Land measurements Land Measurements Understanding land measurement and terms is vital to genealogy research. I hope this will help you decipher the wills and land records.

How to read land descriptions OLD SURVEY MEASUREMENTS. Old surveys were often measured using a Surveyors Chain. These were literally chains made up of 100 links. Each Chain was 66 feet long. Each link was 0.666 of a foot...or 7.92" To convert the distances on a plat measured in chains (abbreviate Ch) simply multiply the distance in chains by 66. Another common unit of measurement was the Pole. The Pole is exactly what it sounds like; a wood pole which was 16.5' feet long. To convert the distances on a plat measured in poles (abbreviated P) you must multiply the distance by 16.5 A Pole is sometimes called a "perch"on old surveys. MILES A mile is defined as being 5,280 feet in length. AREA MEASUREMENTS The standard unit of measuring land in the United States is the ACRE. An Acre is equal to 43,560 square feet (Sq. Ft.) of area.

An acre is also equal to 10 square chains ( 66 x 66 x 10 = 43560 Sq. Ft.) or 160 square rods (16.5 x 16.5 x 160 = 43,560 Sq. Ft.) There are exactly 640 Acres in one square mile. Seeing how older units of measurement like the chain and the pole can be converted into acres it is easy to see that seemingly odd distances (66' and 16.5') really did make sense. WHAT DOES AN ACRE LOOK LIKE? If you had a parcel of land that was exactly 1 acre in size and was perfectly square it would be 208.71' on each of the 4 sides. If the same lot were a rectangle 100' wide it would be 435.60' feet deep (long). Manual of Instructions for the Survey of the Public Lands of the United States; 1973 Prepared by the Bureau of Land Management, Technical Bulletin 6; pub. U.S.

Dept of Interior Methods of Survey The methods described in this chapter comprise the specifications for determining the length and direction of lines. DISTANCE MEASUREMENT Units 2-1. The law prescribes the chain as the unit of linear measure for the survey of the public lands. All returns of measurements in the rectangular system are made in the true horizontal distance in miles, chains, and links. (Exceptions are special requirements for measurement in feet in townsite surveys, chapter VII, and mineral surveys, chapter X.) Units of Linear Measure 640 acres The chain unit, devised in the seventeenth century by Edmund Gunter, an English astronomer, is so designed that 10 square chains are equivalent to one acre. In the English colonial area of the United States the boundaries of land were usually measured in the chain unit, but lengths of lines were frequently expressed in poles. One pole is equal to 25 links, and four poles equal one chain. The field notes of some early rectangular surveys in the southern States show the distance in "perches," equivalent to poles. The term now commonly used for the same distance is the rod. Land grants by the French crown were made in arpents.

The arpent is a unit of area, but the side of a square arpent came to be used for linear description. The Spanish crown and the Mexican Government granted lands which were usually described in linear varas. Both the arpent and the vara have slightly different values in different States. The conversions most often needed are shown in the Standard Field Tables. Convert chain to foot - Conversion of Measurement Units ›› More information from the unit converter How many chain in 1 foot? The answer is 0.0151514848485. We assume you are converting between chain [Gunter, survey] and foot. You can view more details on each measurement unit: The SI base unit for length is the metre. 1 metre is equal to 0.0497095959596 chain, or 3.28083989501 foot. Note that rounding errors may occur, so always check the results. Use this page to learn how to convert between chains and feet. Type in your own numbers in the form to convert the units! ›› Want other units?

You can do the reverse unit conversion from foot to chain , or enter any two units below: Enter two units to convert From: I'm feeling lucky, show me some random units . ›› Definition: Foot A foot (plural: feet) is a non-SI unit of distance or length, measuring around a third of a metre. There are twelve inches in one foot and three feet in one yard. ›› Metric conversions and more ConvertUnits.com provides an online conversion calculator for all types of measurement units. You can find metric conversion tables for SI units, as well as English units, currency, and other data. Type in unit symbols, abbreviations, or full names for units of length, area, mass, pressure, and other types. Examples include mm, inch, 100 kg, US fluid ounce, 6'3", 10 stone 4, cubic cm, metres squared, grams, moles, feet per second, and many more!

Question: How many links are there in a surveyor's chain?
Answer: One Hundred